Some Memories Never Die

TORONTO – All good things must come to an end, and that includes memory components.

But while Windows XP users were forced to upgrade to a new operating system when Microsoft ended support, end-of-life (EOL) memory by major vendors is not always the final nail in the coffin, and there are customers who have valid reasons for wanting to stick with what works.

In an era where memory is rapidly evolving to keep up with the performance requirements, the idea that there’s still life for older memory might seem odd, but as Jim Handy, principal analyst with Objective Analysis, tells me, there are a number of industries employing equipment with significantly long life spans that have specific memory requirements, including the telecommunications industry. And while components including memory may not last as long as equipment such as networking gear, these companies want to be able to replace failed memory with something exactly the same, and ideally, not have to requalify it, because this equipment has been in use for decades and is still expected to last for years to come.

This where is a company such as a Alliance Memory steps in. The San Carlos, Calif.-based company is a fabless semiconductor company that focuses on manufacturing legacy SRAM, DRAM, and SDRAM ICS, and it is always looking to expand its portfolio to support customers that EOL memories.

Most recently, Alliance Memory announced it would extend the life of several EOL products from Micron, including three 512M SDRAM devices that Micron discontinued, including both the commercial and industrial temperature 32M x 16 MT48LC32M16A2P-75:C and commercial temperature 64M x 8 MT48LC64M8A2P-75:C. In addition to the part numbers, the company will also offer Alliance-marked 512M SDRAMs manufactured by Micron, which will be 100% identical to the Micron parts.

Offered in a 54-pin TSOP II package, these devices are optimized for medical, industrial, automotive, and telecom applications requiring high memory bandwidth, according to David Bagby, president of Alliance Memory. Devices with the Alliance Memory part numbers are 100% equivalent to the corresponding Micron part number, he said, and each device has been manufactured to the same wafer/assembly and test materials and process as the corresponding Micron part number, with only the top-side marking being different. The agreement with Micron is somewhat unique for Alliance Memory, said Bagby, in that it is a formal partnership and Micron will manufacture these devices.

In general, Bagby said Alliance Memory is always looking to expand its portfolio of memory products that include EOLed products from major vendors, although he noted that those vendors have shrunk significantly over the years with Micron, Samsung, and SK Hynix being the main players.

Bagby said customers are often not aware there are options when memory products hits EOL; the deal with Micron enables them to keeping buying the same components without requalifying, something Objective Analysis’ Handy said can be a cost-prohibitive process depending on the use case and equipment.

Bagby said even if a customer ends up buying an Alliance Memory-manufactured version of an EOL product, requalifying the memory can still be a much more affordable option than replacing the equipment that needs an EOL component. And although it’s inevitable that all memory products eventually become obsolete, Bagby said Alliance memory is committed to long-term support of EOL products if it’s profitable.

Most of the companies focusing on the same market as Alliance Memory are based in Asia and do not have a high profile, said Bagby, noting the other vendor that has significant visibility is Milpitas, Calif.-based Integrated Silicon Solutions Inc.

@msporer: Right, the masks are unusuable, but per my understanding this is an inventory of finished wafers that Alliance took from Micron. Nobody can tell for how long this lasts, which is a certain risk that supply can end at any time without notice.

Obsolescence management is important, but it is difficult to impossible for customers to perfectly estimate the future need and place an exactly matching Last Time Buy quantity.

If a replacement made in a newer process technology is available (as for these parts there is, see the message from nurbano), it makes more sense to approve that and keep the freedom of booking 'on demand'.

Saving the masks is not enough. Most memories are run on proprietary processes unique to the manufacturer. Once that process is removed from the fab the old masks are worthless. The volumes needed on the old devices never justify investing in a new design. The onus is on the customers to manage their obsolescence requirements.

@nurbano: You are right. The Micron/Alliance part is a dinosaur manufactured in a 115nm process, which is around 10 years old. There is for sure no more production possible of these parts, so Alliance might just sell off the old wafer-stock from Micron, lasting for an unknown period of time.

Intelligent Memory confirmed using a current 45nm process.

A simple cross reference list:

512Mb x16 TSOP54 MT48LC32M16A2P -> IM5116SDBBTG

256Mb x8 TSOP54 MT48LC32M8A2P -> IM2508SDBBTG

256Mb x16 TSOP54 MT48LC16M16A2P -> IM2516SDBATG

Many small form factor customers use BGA54 packages which Micron had only up to 256Mb, but IM offers these up to 512Mb !

Sustainability is certainly an issue. There is a limitation as to how long and how many of this version will be produced, specifically regarding the device noted in the article. If anyone reading here has designed around this density of SDR, then you are keenly aware of just how difficult a part it has become to source.

For longer sustainability, I would recommend looking into Intelligent Memory. They have released a sustainable, new revision of the 512Mb SDR that is pin for pin compatible along with several other densities.

You are right, but in today's era there is not a single person who gets tied up with one company or organisation for longer duration, everyone is jumping here and there for salary hikes, technical people does not believe in getting associated with one company for long, at the same time companies are also not looking for long-term associations with employees as their targets are promoting short term job durations. So in this case does any buddy will be looking for 10-20 year product continuation? Infect no one will be worried about it in any organisation.

@elizabethsimon: It is a 16-MBit (1M x 16) 3.0V burst mode only NOR FLASH originally from AMD and then acquired by Spansion. This has gone EOL phase quite sometime back (more than a couple of years). I don't remember the part# now, it might be something like S29AL016xxx (AM29LV160xxx) if I remember it correct.

@Sanjib: if the chip vendor still has the mask sets stored away some where, there is a possibility that you can run many wafer lots and package them. There are many OSATS in Philippines and Malaysia that run lines of TSSOPs, TOs, etc. They will cost more since the volumes will be low.

For FLASH memory, it depends on what part you are trying to replace. I'm also working for a company with long life span products and have had some experience with FLASH obsolescence. For most 5V FLASH parts I was not able to find replacements that met our requirements. I was able to replace one of the obsolete parts with a Micron part and also looked at parts from AMIC and Macronix which almost worked.

I've been with this company for about 6 years and have been involved with three rounds of FLASH obsolescense so I understand what a pain it can be.

@Kinnar, parts obsolescence has to be managed as a risk to the product just like any other. Even if companies like this extend the lifetime of components there is the risk that the price will go up. As you point out, lower volumes can cause that, particularly if the manufacture of the parts goes into a single-source. Companies really need to plan ahead for obsolescence and create alternatives for themselves to avoid being boxed into a corner. Too many of them don't do this and instead just react.